Display device and method of manufacturing the same

ABSTRACT

A display device and a method of manufacturing the same are disclosed. In one aspect, the display device includes a substrate including a separation area and a plurality of pixel formed over the substrate. The separation area is formed between adjacent pixels, and a plurality of through holes are respectively defined by a plurality of surrounding inner surfaces of the separation area, and wherein each of the inner surfaces passes through the substrate. The display device also includes an encapsulation layer formed over the substrate and covering the inner surfaces of the separation area.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

This application claims the benefit of Korean Patent Application No.10-2014-0191126, filed on Dec. 26, 2014, in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein in itsentirety by reference.

BACKGROUND

Field

The described technology generally relates to a display device and amethod of manufacturing the same.

Description of the Related Technology

The use of display devices is being diversified due to their thinprofile and light weight. Existing displays are being replaced byportable and thin flat panel displays. Generally, its thin profile andassociated difficulty with manufacturing, causes concerns about thedurability of devices. Bending and folding are in high demand, butmanufacturing display devices that are both flexible and durable ischallenging. For this reason, there are limits in enhancing the userexperience with their constraints.

SUMMARY OF CERTAIN INVENTIVE ASPECTS

One inventive aspect relates to a display device and a method ofmanufacturing the same, which enhance a user's convenience.

Another aspect is a display device that includes: a substrate; aplurality of pixel units that are formed on the substrate; a separationarea that is defined on the substrate and are formed between twoadjacent pixel units among the plurality of pixel units; a through partthat is formed in the separation area and includes an inner surfacepassing through the substrate; and an encapsulation layer that is formedon the substrate and covers the inner surface of the through part,wherein an organic layer and an inorganic layer are alternately formedin the encapsulation layer to seal the plurality of pixel units.

The inner surface of the through part can have a slope.

The inner surface of the through part can have a step height.

Each of the plurality of pixel units can include: a pixel electrode thatis formed on the substrate; an intermediate layer that includes anemission layer formed on the pixel electrode; and an opposite electrodethat is formed to be opposite to the pixel electrode and covers theintermediate layer.

The inner surface of the through part can have a width which is narrowedin a direction from the opposite electrode to the substrate.

The separation area can include a first separation area and a secondseparation area, and the first separation area can include a regionbetween two pixel units, which are adjacent to each other in a firstdirection, among the plurality of pixel units. The second separationarea can include a region between two pixel units, which are adjacent toeach other in a second direction intersecting the first direction, amongthe plurality of pixel units. The through part can include a firstthrough part and a second through part. The first through part can beformed in the first separation area, and the second through part can beformed in the second separation area.

The first through part can have a shape that long extends along thesecond direction, and the second through part can have a shape that longextends along the first direction.

The display device can further include one or more wirings that areelectrically connected to the plurality of pixel units, wherein the oneor more wirings are formed not to overlap the through part.

The one or more wirings can extend in one direction and are formed to becurved and to protrude in another direction, intersecting the onedirection, along a periphery of the through part which is formed in theother direction intersecting the one direction.

The one or more wirings can include a plurality of wirings, and twowirings, which are adjacent to each other in one direction, among theplurality of wirings can be symmetrical about the through part.

The substrate can have flexibility.

Another aspect is a method of manufacturing a display device thatincludes: providing a substrate that includes a pixel area in which aplurality of pixel units are formed and a separation area that is formedbetween two adjacent pixel units among the plurality of pixel units;forming the plurality of pixel units on the substrate; forming a throughpart, which includes an inner surface passing through the substrate, inthe separation area of the substrate; and forming an encapsulationlayer, which covers the inner surface of the through part, on thesubstrate and, wherein an organic layer and an inorganic layer arealternately formed in the encapsulation layer to seal the plurality ofpixel units.

The forming of the through part can include forming the inner surface ofthe through part to have a slope or a step height.

The forming of the plurality of pixel units can include: forming a pixelelectrode on the substrate; forming an intermediate layer, whichincludes an emission layer, on the pixel electrode; and forming anopposite electrode that covers the intermediate layer and is opposite tothe pixel electrode.

The forming of the through part can include forming the inner surface ofthe through part for a width to be narrowed in a direction from theopposite electrode to the substrate.

The method can further include forming a thin film transistor, whichincludes a semiconductor layer, a gate electrode, a source electrode,and a drain electrode, on the substrate. The forming of the thin filmtransistor can include: forming a gate insulating layer between thesemiconductor layer and the gate electrode; forming an interlayerinsulating layer between the gate electrode and the source electrode anddrain electrode; and forming a contact hole, which enables thesemiconductor layer to be electrically connected to the source electrodeand the drain electrode, in the gate insulating layer and the interlayerinsulating layer. The forming of the through part can include: forming afirst through hole; forming a second through hole; forming a thirdthrough hole; and forming a fourth through hole. The forming of thecontact hole and the forming of the first through hole can besimultaneously performed.

The method can further include forming a first insulating layer, inwhich a hole exposing one of the source electrode and drain electrode ofthe thin film transistor is formed, on the thin film transistor, whereinthe forming of the first insulating layer and the forming of the secondthrough hole can be simultaneously performed.

The method can further include forming a second insulating layer,including an opening that exposes a center portion of the pixelelectrode, on the first insulating layer, wherein the forming of thesecond insulating layer and the forming of the third through hole can besimultaneously performed.

The forming of the fourth through hole can include removing a portion ofthe substrate corresponding to the first through hole to form the fourththrough hole.

The providing of the substrate can include forming the substrate with amaterial having flexibility.

Another aspect is a display device comprising: a substrate including aseparation area;

a plurality of pixel formed over the substrate, wherein the separationarea is formed between adjacent pixels, wherein a plurality of throughholes are respectively defined by a plurality of surrounding innersurfaces of the separation area, and wherein each of the inner surfacespasses through the substrate; and an encapsulation layer formed over thesubstrate and covering the inner surfaces of the separation area.

In the above display device, at least one of the inner surfaces has aslope.

In the above display device, at least one of the inner surfaces has astep shape.

In the above display device, each of the pixels comprises: a pixelelectrode formed over the substrate; an intermediate layer including anemission layer formed over the pixel electrode; and an oppositeelectrode formed opposite to the pixel electrode and at least partiallycovering the intermediate layer.

In the above display device, at least one of the inner surfaces has agreater width adjacent to the opposite electrode than the substrate.

The display device of claim 1, wherein the separation area comprises afirst separation area and a second separation area, wherein the firstseparation area comprises a region formed between first pixels, adjacentto each other in a first direction, among the pixels, wherein the secondseparation area comprises a region formed between second pixels,adjacent to each other in a second direction crossing the firstdirection, among the pixels, wherein the through hole comprises firstand second through holes respectively formed in the first and secondseparation areas.

In the above display device, the first through hole extends in thesecond direction, wherein the second through hole extends in the firstdirection.

The above display device further comprises one or more wiringselectrically connected to the pixels, wherein the wirings do not overlapthe through hole in a direction crossing the first and seconddirections.

In the above display device, the wirings extend in one of the first andsecond directions, wherein the wirings protrude in the other directionso as to curve around a periphery of the through hole.

In the above display device, the wirings comprise a plurality ofwirings, wherein two of the wirings, adjacent to each other in one ofthe first and second directions, are substantially symmetrical withrespect to the through hole.

In the above display device, the substrate is flexible.

Another aspect is a method of manufacturing a display device, the methodcomprising: providing a substrate including a pixel area and aseparation area; forming a plurality of pixels in the pixel area,wherein the separation area is located between adjacent pixels; forminga plurality of through holes respectively defined by a plurality ofsurrounding inner surfaces of the separation area, wherein each of theinner surfaces passes through the substrate; and forming anencapsulation layer over the substrate so as to cover the inner surfacesof the through hole.

In the above method, the forming of the through hole comprises formingat least one of the inner surfaces to have a slope or a step shape.

In the above method, the forming of the pixels comprises: forming apixel electrode over the substrate; forming an intermediate layerincluding an emission layer over the pixel electrode; and forming anopposite electrode at least partially covering the intermediate layerand opposite to the pixel electrode.

In the above method, the forming of the through holes comprises formingat least one of the inner surfaces having a greater width adjacent tothe opposite electrode than the substrate.

The above method further comprises forming a thin film transistor (TFT),including a semiconductor layer and gate, source and drain electrodes,over the substrate, wherein the forming of the TFT comprises: forming agate insulating layer between the semiconductor layer and the gateelectrode; forming an interlayer insulating layer between the gate andsource electrodes and between the gate and drain electrodes; and forminga contact hole, through which the semiconductor layer is electricallyconnected to the source and drain electrodes, in the gate and interlayerinsulating layers, wherein the forming of the through holes comprisesforming first to fourth through holes consecutively, and wherein theforming of the contact hole and the forming of the first through holeare concurrently performed.

The above method further comprises forming a first insulating layer overthe TFT, wherein the first insulating layer includes a hole exposing oneof the source and drain electrodes of the TFT, and wherein the formingof the first insulating layer and the forming of the second through holeare concurrently performed.

The above method further comprises forming a second insulating layer,including an opening that exposes a center portion of the pixelelectrode, over the first insulating layer, wherein the forming of thesecond insulating layer and the forming of the third through hole areconcurrently performed.

In the above method, the forming of the fourth through hole comprisesremoving a portion of the substrate corresponding to the first throughhole.

In the above method, at least one of the through holes is formed betweenfour adjacent pixels.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view schematically illustrating a display deviceaccording to an exemplary embodiment.

FIG. 2 is a plan view schematically illustrating an enlarged portion Aof FIG. 1.

FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2.

FIGS. 4A to 4C are cross-sectional views taken along line VI-VI of FIG.2.

FIG. 5 is a plan view schematically illustrating the enlarged portion Aof FIG. 1.

FIG. 6 is a plan view schematically illustrating the enlarged portion Aof FIG. 1.

FIG. 7 is a plan view schematically illustrating an enlarged portion Kof FIG. 6.

FIGS. 8 to 12 are cross-sectional views schematically illustrating aprocess of manufacturing a display device, according to an exemplaryembodiment.

DETAILED DESCRIPTION OF CERTAIN INVENTIVE EMBODIMENTS

Reference will now be made in detail to exemplary embodiments, examplesof which are illustrated in the accompanying drawings, wherein likereference numerals refer to like elements throughout. In this regard,the present exemplary embodiments can have different forms and shouldnot be construed as being limited to the descriptions set forth herein.Accordingly, the exemplary embodiments are merely described below, byreferring to the figures, to explain aspects of the present description.

Embodiments can impose various transformations that can have variousembodiments, and specific embodiments illustrated in the drawings willbe described in detail in the detailed description. The effects andfeatures of the described technology will become apparent from thefollowing description of the embodiments with reference to theaccompanying drawings, which is set forth hereinafter. The describedtechnology can, however, can be embodied in different forms and shouldnot be construed as being limited to the embodiments set forth herein.

Hereinafter, embodiments of the described technology will be describedin detail with reference to the accompanying drawings. In addition, inthe present specification and drawings, like reference numerals refer tolike elements throughout, and thus, redundant descriptions are omitted.

In the following embodiments, the terms “first” and “second” are fordifferentiating one element from another element, and these elementsshould not be limited by these terms. In the following embodiments, thesingular forms “a”, “an” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise.

In the following embodiments, it should be further understood that theterms “comprises”, “comprising”, “has”, “having”, “includes” and/or“including”, when used herein, specify the presence of stated features,integers, steps, operations, elements, and/or components, but do notpreclude the presence or addition of one or more other features,integers, steps, operations, elements, components, and/or groupsthereof. Also, when an element such as a layer or a region is referredto as being “on” another element, this includes a case where one elementis formed between other elements, in addition to a case where oneelement is formed directly on the other element.

In the drawings, the dimensions of layers and regions are exaggerated orreduced for clarity of illustration. For example, a dimension andthickness of each element in the drawings are arbitrarily illustratedfor clarity, and thus, embodiments of the described technology are notlimited thereto.

In the following examples, the x-axis, the y-axis and the z-axis are notlimited to three axes of the rectangular coordinate system, and can beinterpreted in a broader sense. For example, the x-axis, the y-axis, andthe z-axis can be perpendicular to one another, or can representdifferent directions that are not perpendicular to one another.

When a certain embodiment can be implemented differently, a specificprocess order can be performed differently from the described order. Forexample, two consecutively described processes can be performedsubstantially at the same time or performed in an order opposite to thedescribed order. In this disclosure, the term “substantially” includesthe meanings of completely, almost completely or to any significantdegree under some applications and in accordance with those skilled inthe art. Moreover, “formed on” can also mean “formed over.” The term“connected” can include an electrical connection.

FIG. 1 is a plan view schematically illustrating a display device 1according to an exemplary embodiment. FIG. 2 is a plan viewschematically illustrating an enlarged portion A of FIG. 1.

Referring to FIGS. 1 and 2, the display device 1 includes a substrate100. A display area DA and a non-display area NDA are defined on thesubstrate 100. One or more pixel units PU and through parts or throughholes 400 are formed in the display area DA.

The substrate 100 can be formed of various materials. The substrate 100can be formed of glass, metal, an organic material, or other materials.For example, the substrate 100 is formed of a flexible material. Thatis, the substrate 100 can be formed of a material which is bent, curved,and folded or rolled. The flexible material forming the substrate 100can be thin glass, metal, or plastic. When the substrate 100 includesplastic, the flexible substrate 100 can be formed of a plastic materialsuch as polyethylene terephthalate (PET), polyethylene naphthalate(PEN), or polyimide which has good heat resistance and durability andenables a curve to be implemented.

The substrate 100 can be divided into the display area DA and thenon-display area NDA. The display area DA is an area in which aplurality of pixel units or plurality of pixels PU are arranged, and candisplay an image. The display area DA can include a pixel area, in whichthe pixel units PU are arranged, and a separation area between adjacentpixel areas. Each of the pixel units PU can include a display device(not shown) so as to implement visible light.

The non-display area NDA can be formed to be adjacent to the displayarea DA. In FIG. 1, the non-display area NDA is illustrated to surroundthe display area DA. In some embodiments, the non-display area NDA isformed to be adjacent to one side of the display area DA. In some otherembodiments, the non-display area NDA is formed to be adjacent to twosides or three sides of the display area DA. Also, depending on thecase, only the display area DA can be formed on the substrate 100. Thatis, although not shown, in some embodiments, the non-display area NDA isnot formed on the substrate 100, and only the display area DA is formedon the substrate 100.

The one or more pixel units PU and through parts 400 can be formed inthe display area DA. In this case, a separation area BA can be formedbetween one pixel unit PU and another pixel unit PU adjacent thereto.The through parts 400 can be formed in the separation area BA. Dependingon the case, the through part 400 can be formed to be separated from thepixel unit PU.

Each of the pixel units PU includes the display device, which can be anorganic light-emitting diode (OLED) or a liquid crystal device. Thiswill be described below in detail.

The through parts 400 are formed on the substrate 100. That is, each ofthe through parts 400 is formed to include an inner surface which passesthrough the substrate 100. For example, the through parts 400 are formedby removing one region of the substrate 100 through a process such asetching. As another example, the substrate 100 is formed to include thethrough parts 400 in manufacturing the substrate 100. The process offorming the through parts 400 on the substrate 100 can vary, and amethod of manufacturing the through parts 400 is not limited. Each ofthe through parts 400 can have a shape which extends in the separationarea BA from one pixel unit PU to another pixel unit PU adjacentthereto.

Each of the through parts 400 includes a first through part 410 and asecond through part 420. The separation area BA includes a firstseparation area BA1 and a second separation area BA2. The first throughpart 410 is formed in the first separation area BA1, and the secondthrough part 420 is formed in the second separation area BA2.Hereinafter, the through parts 400 will be described in detail.

The separation area BA includes the first separation area BA1 and thesecond separation area BA2. It can be understood that the firstseparation area BA1 is an area between two pixel units PU which areadjacent to each other in a first direction, for example, an X axisdirection of FIG. 2. It can be understood that the second separationarea BA2 is an area between two pixel units PU which are adjacent toeach other in a second direction, for example, a Y axis direction ofFIG. 2. Depending on the case, the first direction can be substantiallyperpendicular to or crossing the second direction.

The first through part 410 of each of the through parts 400 can beformed in the first separation area BA1. The first through part 410 canhave a shape which extends along a direction (for example, the seconddirection (the Y axis direction)) intersecting the first direction (theX axis direction).

In some embodiments, the first through part 410 is formed to passthrough the first separation area BA1, and for example, formed tocorrespond to an area in which an area extending from the firstseparation area BA1 overlaps an area extending from the secondseparation area BA2.

Moreover, the first through part 410 can extend in the second directionto the first separation area BA1 between two adjacent pixel units PU,which are adjacent to each of two pixel units PU, which are adjacent toeach other in the first direction, in the second direction, in additionto the first separation area BA1 between the two pixel units PU whichare adjacent to each other in the first direction.

Therefore, the first through part 410 can correspond to one side of eachof the two pixel units PU which are adjacent to each other in the firstdirection, and correspond to one side of each of the two pixel units PUwhich are adjacent to each of the two pixel units PU in the seconddirection. For example, four pixel units PU are formed around one firstthrough part 410.

For example, as illustrated in FIG. 2, two pixel units PU arerespectively formed at a left side and a right side with the firstthrough part 410 therebetween to correspond to each other, on the firstthrough part 410. Two pixel units PU can be respectively formed at aleft side and a right side with the first through part 410 therebetweento correspond to each other, under the first through part 410.

The second through part 420 of each of the through parts 400 can beformed in the second separation area BA2. The second through part 420can extend along a direction (for example, the first direction)intersecting the second direction.

In some embodiments, the second through part 420 is formed to passthrough the second separation area BA2, and for example, is formed tocorrespond to an area in which an area extending from the secondseparation area BA2 overlaps an area extending from the first separationarea BA1.

Moreover, the second through part 420 can extend in the first directionto the second separation area BA2 between two adjacent pixel units PU,which are adjacent to each of two pixel units PU, which are adjacent toeach other in the second direction, in the first direction, in additionto the second separation area BA2 between the two pixel units PU whichare adjacent to each other in the second direction.

Therefore, the second through part 420 may correspond to one side ofeach of the two pixel units PU which are adjacent to each other in thesecond direction, and correspond to one side of each of the two pixelunits PU which are adjacent to each of the two pixel units PU, which areadjacent to each other in the second direction, in the first direction.For example, four pixel units PU are formed with respect to one secondthrough part 420.

As illustrated in FIG. 2, two pixel units PU are respectively formed atan upper side and a lower side with respect to the second through part420, on a left side of the second through part 420. Two pixel units PUcan be respectively formed at an upper side and a lower side withrespect to the second through part 420, on a right side of the secondthrough part 420.

The first through part 410 and the second through part 420 can beseparated from each other. Referring to FIG. 2, in the display device 1,the through parts 400 are formed on the substrate 100, and each of thethrough parts 400 includes a plurality of the first through parts 410and a plurality of second through parts 420.

Moreover, the second through part 420 can be formed between two adjacentfirst through parts 410 among the first through parts 410. The firstthrough part 410 can be formed between two adjacent second through parts420.

FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2. InFIG. 3, the display area DA of the display device 1 will be described indetail. As described above, a plurality of display devices formed in thedisplay area DA can be OLEDs or liquid crystal devices. In the presentembodiment, a display device including OLEDs will be described.

Referring to FIG. 3, a thin film transistor TFT and a capacitor CAP areformed on the substrate 100, and an OLED electrically connected to thethin film transistor TFT is formed on the substrate 100. The thin filmtransistor TFT includes a semiconductor layer 120, a gate electrode 140,a source electrode 160, and a drain electrode 162 and can be formed ofamorphous silicon, polycrystalline silicon, or an organic semiconductormaterial. Hereinafter, a general configuration of the thin filmtransistor TFT will be described in detail.

A buffer layer 110 which is formed of silicon oxide or silicon nitridecan be formed on the substrate 100 so as to planarize a surface of thesubstrate 100 or prevent impurities from penetrating into thesemiconductor layer 120 of the thin film transistor TFT, and thesemiconductor layer 120 can be formed on the buffer layer 100.

The gate electrode 140 is formed on the semiconductor layer 120. In thiscase, the source electrode 160 and the drain electrode 162 areelectrically connected to each other according to a signal applied tothe gate electrode 140. The gate electrode 140 can be formed of a singlelayer or a multilayer formed of aluminum (Al), platinum (Pt), palladium(Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium(Nd), iridium (Jr), chromium (Cr), lithium (Li), calcium (Ca),molybdenum (Mo), titanium (Ti), tungsten (W), and/or copper (Cu) inconsideration of adhesiveness to an adjacent layer, a surface flatnessof a stacked layer, and processability.

In this case, a gate insulating layer 130 which is formed of siliconoxide and/or silicon nitride can be formed between the semiconductorlayer 120 and the gate electrode 140, for securing dielectric propertiesbetween the semiconductor layer 120 and the gate electrode 140.

An interlayer insulating layer 150 can be formed on the gate electrode140, and can be formed of a single layer or a multilayer with siliconoxide or silicon nitride.

The source electrode 160 and the drain electrode 162 are formed on theinterlayer insulating layer 150. The source electrode 160 and the drainelectrode 162 are electrically connected to the semiconductor layer 120through respective contact holes which are formed in the interlayerinsulating layer 150 and the gate insulating layer 130. The sourceelectrode 160 and the drain electrode 162 can be formed of a singlelayer or a multilayer formed of aluminum (Al), platinum (Pt), palladium(Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium(Nd), iridium (Jr), chromium (Cr), lithium (Li), calcium (Ca),molybdenum (Mo), titanium (Ti), tungsten (W), and/or copper (Cu) inconsideration of conductivity.

Although not shown, a protective layer (not shown) which covers the thinfilm transistor TFT can be formed for protecting the thin filmtransistor TFT having the structure. The protective layer can be formedof, for example, an organic material such as silicon oxide, siliconnitride, or silicon oxynitride.

A first insulating layer 170 can be formed on the substrate 100. In thiscase, the first insulating layer 170 can be a planarizing a layer of aprotective layer. When an OLED is formed on the thin film transistorTFT, the first insulating layer 170 planarizes a top of the thin filmtransistor TFT and protects the thin film transistor TFT and variousdevices. The first insulating layer 170 can be formed of, for example,an acryl-based organic material or benzocyclobutene (BCB). In this case,as illustrated in FIG. 10, the buffer layer 110, the gate insulatinglayer 130, the interlayer insulating layer 150, and the first insulatinglayer 170 can be formed over the substrate 100.

A second insulating layer 180 can be formed on the thin film transistorTFT. In this case, the second insulating layer 180 can be a pixel unitdefining layer. The second insulating layer 180 can be formed on thefirst insulating layer 170 and can have an opening. The secondinsulating layer 180 defines a pixel area on the substrate 100.

The second insulating layer 180 can be formed of, for example, anorganic insulating layer. The organic insulating layer can be formed ofan acryl-based polymer such as poly(methyl methacrylate) (PMMA),polystyrene (PS), polymer derivatives containing a phenol group, animide-based polymer, an arylether-based polymer, an amide-based polymer,a fluorine-based polymer, a p-xylene-based polymer, a vinylalcohol-based polymer, or a compound thereof.

An OLED 200 can be formed on the second insulating layer 180. The OLED200 can include a pixel unit electrode 210, an intermediate layer 220including an emission layer (EML), and an opposite electrode 230.

The pixel unit electrode 210 can be formed as a (semi)transparentelectrode or a reflective electrode. When the pixel unit electrode 210is formed as the (semi)transparent electrode, the pixel unit electrode210 can be formed of, for example, indium-tin-oxide (ITO),indium-zinc-oxide (IZO), zinc oxide (ZnO), indium oxide (In₂O₃), indiumgallium oxide (IGO), or aluminum zinc oxide (AZO). When the pixel unitelectrode 210 is formed as the reflective electrode, the pixel unitelectrode 210 can further include a reflective layer, which is formed ofAg, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or a compound thereof, and alayer which is formed of ITO, IZO, ZnO, In₂O₃, IGO, or AZO. However, thepresent embodiment is not limited thereto. For example, the pixel unitelectrode 210 can be formed of various materials, and a structure of thepixel unit electrode 210 can be variously modified to include a singlelayer or a multilayer.

The intermediate layer 220 can be formed in the pixel area defined bythe second insulating layer 180. The intermediate layer 220 includes theEML that emits light according to an electrical signal, and can includea hole injection layer (HIL) and a hole transport layer (HTL), which areformed between the EML and the pixel unit electrode 210, and an electrontransport layer (ETL) and an electron injection layer (EIL) which areformed between the EML and the opposite electrode 230, in addition tothe EML. The HIL, the HTL, the ETL, and the EIL can be stacked in asingle structure or a complex structure. The intermediate layer 220 isnot limited thereto, and can have various structures.

The opposite electrode 230, which covers the intermediate layer 220including the EML and is opposite to the pixel unit electrode 210, canbe formed over the substrate 100. The opposite electrode 230 can beformed as a transparent (or semi-transparent) electrode or a reflectiveelectrode.

When the opposite electrode 230 is formed as the (semi)transparentelectrode, the opposite electrode 230 can include a layer, which isformed of metal (i.e., Li, Ca, LiF/Ca, LiF/Al, Al, Ag, Mg, or a compoundthereof) having a small work function, and a (semi)transparentconductive layer formed of ITO, IZO, ZnO, or In₂O₃. When the oppositeelectrode 230 is formed as the reflective electrode, the oppositeelectrode 230 can include a layer which is formed of Li, Ca, LiF/Ca,LiF/Al, Al, Ag, Mg, or a compound thereof. A configuration and amaterial of the opposite electrode 230 are not limited thereto, and canbe variously modified.

Referring to FIG. 3, an encapsulation layer 300 is formed on thesubstrate 100 to cover the OLED 200. Although not shown in FIG. 3, theencapsulation layer 300 can have a multi-layer structure in which one ormore inorganic layers (not shown) and organic layers (not shown) arestacked. The reason that the encapsulation layer 300 is formed in amulti-layer structure is because when the encapsulation layer 300 isformed as only an organic layer or an inorganic layer, oxygen ormoisture penetrates into the inside through a fine path which is formedin a layer, and damages a display unit. Pixel units are shut off fromthe outside and sealed by the encapsulation layer 300.

An organic material included in the organic layer includes, for example,acryl-based resin, methacryl-based resin, vinyl-based resin, epoxy-basedresin, urethane-based resin, cellulose-based resin, and/orperylene-based resin.

An inorganic material included in the inorganic layer includes, forexample, silicon nitride, aluminum nitride, zirconium nitride, titaniumnitride, hafnium nitride, tantalum nitride, silicon oxide, aluminumoxide, titanium oxide, tin oxide, cerium oxide, and/or siliconoxynitride (SiON).

FIGS. 4A to 4C are cross-sectional views taken along line VI-VI of FIG.2. In FIGS. 4A to 4C, exemplary embodiments of a structure of thethrough part 400 will be described in detail.

Referring to FIGS. 4A to 4C, the through part 400 is formed in theseparation area BA. In FIGS. 4A to 4C, a cross-sectional surface of thefirst through part 410 formed in the first separation area BA1 isillustrated, but the second through part 420 formed in the secondseparation area BA2 can also have the same structure as that of thefirst through part 410.

Referring to FIG. 4A, the through part 400 is formed to pass through thesubstrate 100 and includes an inner surface 400 a which passes throughthe substrate 100. The inner surface 400 a denotes a cross-sectionalsurface that is formed to pass through the substrate 100 and one or morematerial layers formed on the substrate 100. In some embodiments, theinner surface 400 a of the through part 400 is formed to beapproximately vertical to the substrate 100 or substantiallyperpendicular to a surface of the substrate 100.

The encapsulation layer 300 in which an organic layer and an inorganiclayer are alternately formed can be formed on the OLED and can be formedto cover the inner surface 400 a of the through part 400. When theencapsulation layer 300 is not formed to cover the inner surface 400 a,moisture or impurities can flow into one or more material layers inwhich a cross-sectional surface is exposed due to the inner surface 400a and damage various devices or OLEDs. Therefore, when the encapsulationlayer 300 is sealed to cover the inner surface 400 a, a reliability ofthe display device is enhanced.

Referring to FIG. 4B, the inner surface 400 a is formed to have a slope.That is, the inner surface 400 a can be an inclined surface. The innersurface 400 a can have a shape in which a width is narrowed in adirection from the opposite electrode 230 to the substrate 100. That is,the inner surface 400 a can have a V-shape with the substrate 100 sideopened. A slope of the inner surface 400 a can be formed to make anacute angle with respect to the substrate 100.

The inner surface 400 a having a slope denotes that a cross-sectionalsurface, which is formed to pass through one or more material layersformed on the substrate 100, has a slope. In order to form such anartificial inclined surface, a process of patterning a material layercan use a halftone mask or a slit mask. However, a method of forming athrough hole having an inclined surface in the inner surface 400 a isnot limited. Therefore, in forming the encapsulation layer 300, it isvery easy for the encapsulation layer 300 to cover the inner surface 400a of the through hole.

Referring to FIG. 4C, the through part 400 is formed to pass through thesubstrate 100 and includes an inner surface 400 a which passes throughthe substrate 100. The inner surface 400 a denotes a cross-sectionalsurface that is formed to pass through the substrate 100 and one or morematerial layers 190 formed on the substrate 100. The one or morematerial layers 190 include, for example, the buffer layer 110, the gateinsulating layer 130, the interlayer insulating layer 150, the firstinsulating layer 170, and the second insulating layer 180. Therefore,the material layers 190 can include a plurality of end surfaces 110 a,130 a, 150 a, 170 a and 180 a corresponding to the inner surface 400 aof the through part 400.

In some embodiments, the inner surface 400 a is formed in a stair shape.This denotes that each of the end surfaces 110 a, 130 a, 150 a, 170 aand 180 a of the material layers 190 is formed to have a step height.The inner surface 400 a can be formed in order for a width to benarrowed in a direction from the opposite electrode 230 to the substrate100. That is, in FIG. 4C, the end surfaces 110 a, 130 a and 150 a can beformed to protrude toward the through part 400, and the end surfaces 170a and 180 a can be stacked thereon to have a step height. An end surface100 a of the substrate 100 can be formed to have the same plane as thoseof the end surfaces 110 a, 130 a and 150 a, or can be formed to protrudefurther than the end surfaces 110 a, 130 a and 150 a.

In FIG. 4C, the end surfaces 110 a of the buffer layer 110, the endsurface 130 a of the gate insulating layer 130, and the end surface 150a of the interlayer insulating layer 150 are formed on substantially thesame plane. This is because the buffer layer 110, the gate insulatinglayer 130, and the interlayer insulating layer 150 are substantiallysimultaneously or concurrently patterned in a process of forming acontact hole which enables the semiconductor layer 120, the sourceelectrode 160, and the drain electrode 162 to be electrically connectedto each other. However, the present embodiment is not limited thereto.Depending on the case, each of the end surfaces 110 a, 130 a and 150 acan be formed to have a step height.

The encapsulation layer 300 can be formed all over the substrate 100 toseal the OLED and cover the end surfaces 110 a, 130 a, 150 a, 170 a and180 a. Due to an inner structure of the through hole, in forming theencapsulation layer 300, it is very easy for the encapsulation layer 300to cover the inner surface 400 a of the through hole. Therefore, theencapsulation layer 300 is sealed to cover the inner surface 400 a,thereby enhancing a reliability of the display device.

FIG. 5 is a plan view schematically illustrating the enlarged portion Aof FIG. 1.

Referring to FIG. 5, the display device 1 includes the substrate 100 andone or more wirings SL1 to SL3, V1 to V3, and D1 to D3.

The display area DA and the non-display area NDA are defined on thesubstrate 100. The one or more pixel units PU and through parts 400 areformed in the display area DA.

The substrate 100 is divided into the display area DA and thenon-display area NDA. Details of positions of the display area DA andthe non-display NDA are the same as those of the above-describedexemplary embodiment, and thus, their detailed descriptions are notprovided.

The pixel units PU and through parts 400 are formed in the display areaDA. Each of the pixel units PU can include a display element (not shown)so as to emit visible light. This is the same as the above-describedexemplary embodiment, and the structure described above with referenceto FIG. 3 can be applied.

The through parts 400 are formed on the substrate 100. The through parts400 and the separation area BA are as described in the above-describedexemplary embodiment, and thus, their detailed descriptions are notprovided.

The one or more wirings SL1 to SL3, V1 to V3, and D1 to D3 are wiringswhich are electrically connected to the pixel units PU, and are formedto be separated from the through parts 400 without overlapping thethrough parts 400.

The one or more wirings SL1 to SL3, V1 to V3, and D1 to D3 can includeone or more first wirings SL1 to SL3.

The first wirings SL1 to SL3 are electrically connected to the pixelunits PU. In some embodiments, the first wiring SL1 is electricallyconnected to a plurality of pixel units PU which are arranged in one rowin a first direction (an X axis direction of FIG. 5). The first wiringSL1 is formed to have a curve. That is, the first wiring SL1 can includea region, which extends in the first direction, and a region which isbent in a second direction (a Y axis direction of FIG. 5), along aperiphery of the first through part 410. The region which is bent candenote a region which protrudes in the second direction. Therefore, thefirst wiring SL1 is separated from the first through part 410 and thesecond through part 420.

In some embodiments, the first wiring SL1 is electrically connected to aplurality of pixel units PU which are formed under the first wiring SL1,namely, formed to be adjacent to each other in the second directionintersecting the first direction, and are arranged in one row in thefirst direction.

The first wiring SL2 is formed to have a curve. That is, the firstwiring SL2 can include a region, which extends in the first direction,and a region which is bent in the second direction along the peripheryof the first through part 410. The region which is bent in the seconddirection can denote a region which protrudes in the second direction.Therefore, the first wiring SL2 is separated from the first through part410 and the second through part 420.

In some embodiments, the first wiring SL2 is substantially symmetricalwith the first wiring SL1. In some embodiments, the first wiring SL2 andthe first wiring SL1 are substantially symmetrical about the secondthrough part 420.

The first wiring SL3 has the same form as that of the first wiring SL1.The first wiring SL3 can be electrically connected to a plurality ofpixel units PU which are arranged in one row in the first direction (theX axis direction of FIG. 5). The first wiring SL3 is formed to have acurve. That is, the first wiring SL3 can include a region, which extendsin the first direction, and a region which is bent in the seconddirection along the periphery of the first through part 410. The regionwhich is bent in the second direction can denote a region whichprotrudes in the second direction. Therefore, the first wiring SL3 isseparated from the first through part 410 and the second through part420.

Although not shown, a first wiring (not shown) having the same form asthat of the first wiring SL2 can be formed under the first wiring SL3.Also, an arrangement of the first wirings SL1 to SL3 can be repeated.

The first wirings SL1 to SL3 can transfer various signals to the pixelunits PU. In some embodiments, the first wirings SL1 to SL3 transfer ascan signal to the pixel units PU. As another example, the first wiringsSL1 to SL3 are electrically connected to a gate electrode 105 of a thinfilm transistor illustrated in FIG. 7.

The wirings SL1 to SL3, V1 to V3, and D1 to D3 can include one or moresecond wirings V1 to V3. The second wirings V1 to V3 are electricallyconnected to the pixel units PU. In some embodiments, the second wiringV1 is electrically connected to a plurality of pixel units PU which arearranged in one row in the second direction (the Y axis direction ofFIG. 5).

The second wiring V1 is formed to have a curve. That is, the secondwiring V1 can include a region, which extends in the second direction,and a region which is bent in the first direction (the X axis directionof FIG. 5) along a periphery of the second through part 420. The regionwhich is bent in the first direction can denote a region which protrudesin the first direction. Therefore, the second wiring V1 is separatedfrom the first through part 410 and the second through part 420.

In some embodiments, the second wiring V1 can be electrically connectedto a plurality of pixel units PU which are formed to be adjacent to eachother a side direction of the second wiring V1 (for example, a rightside), namely, in the first direction (the X axis direction of FIG. 5)intersecting the second direction, and are arranged in one row in thesecond direction.

The second wiring V2 is formed to have a curve. That is, the secondwiring V2 can include a region, which extends in the first direction,and a region which is bent in the second direction along the peripheryof the first through part 410. The region which is bent in the seconddirection (the Y axis direction of FIG. 5) can denote a region whichprotrudes in the second direction. Therefore, the first wiring SL2 isseparated from the first through part 410 and the second through part420.

In some embodiments, the second wiring V2 can be symmetrical with thesecond wiring V1, and in detail, the second wiring V2 and the secondwiring V1 can be symmetrical about the first through part 410.

The second wiring V3 has the same form as that of the second wiring V1.The second wiring V3 can be electrically connected to a plurality ofpixel units PU which are arranged in one row in the second direction.The second wiring V3 is formed to have a curve. That is, the secondwiring V3 can include a region, which extends in the second direction,and a region which is bent in the first direction along the periphery ofthe second through part 420. The region which is bent in the firstdirection can denote a region which protrudes in the first direction.Therefore, the first wiring SL3 is separated from the first through part410 and the second through part 420.

Although not shown, a second wiring (not shown) having the same form asthat of the second wiring V2 can be formed on the right of the secondwiring V3. Also, an arrangement of the second wirings V1 to V3 can berepeated.

The second wirings V1 to V3 can transfer various signals to the pixelunits PU. In some embodiments, the second wirings V1 to V3 can transfera signal, which is used to supply power, to the pixel units PU. Asanother example, the second wirings V1 to V3 can be electricallyconnected to a first electrode 131 or a second electrode 132 illustratedin FIG. 6 or 7.

The one or more wirings SL1 to SL3, V1 to V3, and D1 to D3 can includeone or more third wirings D1 to D3.

The one or more third wirings D1 to D3 are electrically connected to thepixel units PU. In some embodiments, the third wiring D1 can beelectrically connected to a plurality of pixel units PU which arearranged in one row in the second direction (the Y axis direction ofFIG. 5).

The third wiring D1 is formed to have a curve. That is, the third wiringD1 can include a region, which extends in the second direction, and aregion which is bent in the first direction (the X axis direction ofFIG. 5) along the periphery of the second through part 420. The regionwhich is bent in the first direction can denote a region which protrudesin the first direction. Therefore, the third wiring D1 is separated fromthe first through part 410 and the second through part 420.

In some embodiments, the third wiring D1 can be separated from thesecond wirings V1 to V3. Also, the second through part 420 correspondingto the region of the third wiring D1, that is bent in the firstdirection, can differ from the second through part 420 corresponding toa region of the second wirings V1 to V3, that is bent in the firstdirection. For example, the second through parts 420 are adjacent toeach other.

In some embodiments, the third wiring D2 can be electrically connectedto a plurality of pixel units PU which are formed to be adjacent to eachother a side direction of the third wiring D1 (for example, a rightside), namely, in the first direction (the X axis direction of FIG. 5)intersecting the second direction, and are arranged in one row in thesecond direction.

The third wiring D2 is formed to have a curve. That is, the third wiringD2 can include a region, which extends in the second direction, and aregion which is bent in the first direction along the periphery of thesecond through part 420. The region which is bent in the first directioncan denote a region which protrudes in the first direction. Therefore,the third wiring D2 is separated from the first through part 410 and thesecond through part 420.

In some embodiments, the third wiring D2 is substantially symmetricalwith the third wiring D1. For example, the third wiring D2 and the thirdwiring D1 are substantially symmetrical about the first through part410.

In some embodiments, the third wiring D2 is separated from the secondwirings V1 to V3. Also, the second through part 420 corresponding to theregion of the third wiring D2, which is bent in the first direction, candiffer from the second through part 420 corresponding to the region ofthe second wirings V1 to V3 that is bent in the first direction. Forexample, the second through parts 420 are adjacent to each other.

The third wiring D3 has substantially the same form as that of the thirdwiring D1. The third wiring D3 can be electrically connected to aplurality of pixel units PU which are arranged in one row in the seconddirection. The third wiring D3 is formed to have a curve. That is, thethird wiring D3 can include a region, which extends in the seconddirection, and a region which is bent in the first direction along theperiphery of the second through part 420. The region which is bent inthe first direction can denote a region which protrudes in the firstdirection. Therefore, the third wiring D3 is separated from the firstthrough part 410 and the second through part 420.

In some embodiments, the third wiring D3 is separated from the secondwirings V1 to V3. Also, the second through part 420 corresponding to aregion where the third wiring D3 is bent in a first direction can differfrom the second through part 420 corresponding to a region where thesecond wirings V1 to V3 are bent in the first direction. For example,the second through parts 420 are adjacent to each other.

Although not shown, a third wiring (not shown) having substantially thesame form as that of the third wiring D2 can be formed on the right ofthe third wiring D3. Also, an arrangement of the third wirings D1 to D3can be repeated.

The third wirings D1 to D3 can transfer various signals to the pixelunits PU. In some embodiments, the third wirings D1 to D3 transfer datasignals to the pixel units PU. As another example, the third wirings D1to D3 are electrically connected to a source electrode 107 or a drainelectrode 108 illustrated in FIG. 7.

Although not shown, one of FIGS. 3 to 5 can be selectively applied tothe display device 1.

In some embodiments, the through part 400 is formed on the substrate100. Therefore, a flexibility of the substrate 100 is enhanced, andthus, the weight of the substrate 100 is reduced. Also, when the displaydevice 1 is a bending display device, a flexible display device, or astretchable display device, flexibility is enhanced, and abnormaldeformation is reduced.

In some embodiments, since the through part 400 includes the firstthrough part 410 which extends in one direction and the second throughpart 420 which extends in a direction intersecting the one direction, aflexibility of the substrate 100 is secured even when the substrate 100is bent, curved, or rolled in various directions, an abnormaldeformation of the substrate 100 is prevented, and durability isenhanced. Accordingly, a user's convenience is enhanced when using thedisplay device 1, and the display device 1 is easily applied to, forexample, a wearable device.

Moreover, in some embodiments, the first through part 410 can be formedin a long extended form to correspond to two pixel units PU which areadjacent to each other in one direction and two different pixel units PUadjacent to the two pixel units PU. Thus, a change in a deformationcharacteristic is moderated or reduced on a boundary line between pixelunits PU, thereby enhancing a durability of the display device 1. Also,the first through part 410 is easily applied to the display devicerequiring flexibility, for example, a bending display device, a flexibledisplay device, or a stretchable display device.

Moreover, in some embodiments, the second through part 420 can be formedin a direction intersecting the first through part 410 and can be formedin a long extended form to correspond to two pixel units PU and twodifferent pixel units PU adjacent to the two pixel units PU. Thus, achange in a deformation characteristic is moderated or reduced on aboundary line between pixel units PU, thereby enhancing a durability ofthe display device 1. Also, the second through part 420 is easilyapplied to the display device requiring flexibility, for example, abending display device, a flexible display device, or a stretchabledisplay device.

Moreover, the display device 1 can include the one or more wirings SL1to SL3, V1 to V3, and D1 to D3 which are electrically connected to thepixel units PU. In some embodiments, the one or more wirings SL1 to SL3,V1 to V3, and D1 to D3 are formed to be separated from the through part400 without overlapping the through part 400. Therefore, a flexibilityand a durability of the substrate 100 are enhanced due to the throughpart 400. Also, the wirings SL1 to SL3, V1 to V3, and D1 to D3 can beprevented from being stripped because of not overlapping the throughpart 400, prevented from being polluted by a gas such as externaloxygen, and prevented from being degenerated by moisture.

Kind-based or the same kinds of wirings, namely, the wirings SL1 to SL3,can extend in one direction and have a curved shape, and can be repeatedat certain periods, and thus, a non-uniformity of each pixel unit PUcaused by the wirings SL1 to SL3 is reduced or prevented.

Moreover, the wirings V1 to V3 can extend in one direction and have acurved shape, and can be repeated at certain periods, and thus, anon-uniformity of each pixel unit PU caused by the wirings V1 to V3 isreduced or prevented.

Moreover, the wirings D1 to D3 can extend in one direction and have acurved shape, and can be repeated at certain periods, and thus, anon-uniformity of each pixel unit PU caused by the wirings D1 to D3 isreduced or prevented.

Particularly, the wirings V1 to V3 and wirings D1 to D3, which extend inthe same direction and are electrically connected to a plurality ofpixel units PU which are arranged in the same direction, are formed notto overlap each other, thereby minimizing interference therebetween.Also, curved regions of the wirings V1 to V3 and wirings D1 to D3correspond to different second through parts 420, and thus, anelectrical characteristic of the pixel units PU is prevented from beingreduced due to interference in curved portions of the wirings V1 to V3and wirings D1 to D3.

FIG. 6 is a plan view schematically illustrating the enlarged portion Aof FIG. 1. FIG. 7 is a plan view schematically illustrating an enlargedportion K of FIG. 6.

Referring to FIGS. 6 and 7, the display device 1 includes the substrate100 and the wirings SL1 to SL3, V1 to V3, and D1 to D3.

The display area DA and the non-display area NDA are defined on thesubstrate 100. One or more pixel units PU1 to PU3 and the through parts400 are formed in the display area DA. Each of the pixel units PU1 toPU3 can include a plurality of sub-pixels SP1 to SP3.

The substrate 100 is divided into the display area DA and thenon-display area NDA. The through parts 400 are formed on the substrate100. The substrate 100 and the through parts 400 are as described abovein the above-described exemplary embodiments, and thus, their detaileddescriptions are not provided.

Each of the pixel units PU1 to PU3 can include one or more sub-pixelsSP1 to SP3.

In FIG. 6, three sub-pixels SP1 to SP3 are illustrated, but thedescribed technology is not limited thereto. One pixel unit PU1 caninclude two or four or more sub-pixels. In some embodiments, thesub-pixels SP1 to SP3 included in the one pixel unit PU1 emit visiblelight of different colors. For example, the sub-pixels SP1 to SP3respectively implement red visible light, green visible light, and bluevisible light.

The sub-pixels SP1 to SP3 included in the one pixel unit PU1 can besequentially arranged in one direction, for example, in an X axisdirection with respect to FIG. 6. Also, another pixel unit PU2 adjacentto the one pixel unit PU1 can includes a plurality of pixel units SP1 toSP3, which can be sequentially arranged in a direction intersecting theone direction, for example, a Y axis direction with respect to FIG. 6.

Moreover, another pixel unit PU3 adjacent to the pixel unit PU2 caninclude a plurality of pixel units SP1 to SP3, which can be sequentiallyarranged in a direction intersecting the one direction, for example, inthe X axis direction with respect to FIG. 6. In some embodiments, thepixel units SP1 to SP3 included in the pixel units PU1 to PU3 are all bearranged in one direction (the X axis direction), or are arranged in adirection (the Y axis direction) intersecting the one direction.

The wirings SL1 to SL3, V1 to V3, and D1 to D3 can include the firstwirings SL1 to SL3, second wirings V1 to V3, and third wirings D1 to D3.The first wirings SL1 to SL3, second wirings V1 to V3, and third wiringsD1 to D3 are electrically connected to the pixel units PU1 to PU3. Anarrangement of the first wirings SL1 to SL3, the second wirings V1 toV3, and the third wirings D1 to D3 is substantially the same as that ofthe above-described exemplary embodiment, and thus, its detaileddescriptions are not provided.

The following description will be made with reference to FIG. 7. FIG. 7is a view illustrating the enlarged portion K of FIG. 6.

Referring to FIG. 7, the first wiring SL1 is electrically connected tothe sub-pixels SP1 to SP3 of the pixel unit PU1. The first wiring SL1can have various forms. In some embodiments, the first wiring SL1includes a plurality of connection lines SL1 c which are respectivelyconnected to the sub-pixels SP1 to SP3 and are formed to be separatedfrom each other, a common line SL1 b which is connected to the pluralityof connection lines SL1 c in common, and a body line SP1 a which isconnected to the common line SL1 b and is formed to correspond to a sideof one (for example, the sub-pixels SP1) of the sub-pixels SP1 to SP3.

The second wiring V1 is electrically connected to the sub-pixels SP1 toSP3. The second wiring V1 can have various forms. In some embodiments,the second wiring V1 includes a plurality of connection lines V1 c whichare respectively connected to the sub-pixels SP1 to SP3 and are formedto be separated from each other, a common line V1 b which is connectedto the connection lines V1 c in common, and a body line V1 a which isconnected to the common line V1 b and is formed to correspond to a sideof one (for example, the sub-pixels SP1) of the sub-pixels SP1 to SP3.

The third wiring D1 is electrically connected to the sub-pixels SP1 toSP3 of the pixel unit PU1. The third wiring D1 can have various forms.In some embodiments, the third wiring D1 includes a plurality ofconnection lines D1 c which are respectively connected to the sub-pixelsSP1 to SP3 and are formed to be separated from each other, a common lineD1 b which is connected to the plurality of connection lines D1 c incommon, and a body line D1 a which is connected to the common line D1 band is formed to correspond to a side of one (for example, thesub-pixels SP3) of the sub-pixels SP1 to SP3.

In the display device 1, the through part 400 can be formed on thesubstrate 100. Therefore, a flexibility of the substrate 100 isenhanced, and thus, the weight of the substrate 100 is reduced.

Moreover, the separation area BA between the pixel units PU1 to PU3 isformed on the substrate 100, and thus, when the substrate 100 isdeformed, namely, the substrate 100 is bent, curved, or rolled, thesubstrate 100 is easily deformed near the pixel units PU1 to PU3, and astress caused by deformation is easily reduced or prevented. That is,when the display device 1 is applied as a bending display device, aflexible display device, or a stretchable display device, flexibility isenhanced, and abnormal deformation is reduced.

In some embodiments, since the through part 400 includes the firstthrough part 410 which extends in one direction and the second throughpart 420 which extends in a direction intersecting the one direction, aflexibility of the substrate 100 is secured even when the substrate 100is bent, curved, or rolled in various directions, an abnormaldeformation of the substrate 100 is prevented, and durability isenhanced. Accordingly, a user's convenience is enhanced when using thedisplay device 1, and the display device 1 can be easily applied to awearable device.

Moreover, in some embodiments, the second through part 420 is formedbetween two adjacent first through parts 410 among the first throughparts 410, and thus can prevent a crack from occurring in a lengthdirection of the first through part 410 of the substrate 100 because thefirst through parts 410 extend in one direction.

Moreover, the first through part 410 can be formed between two adjacentsecond through parts 420 among the second through parts 420, and thusprevents a crack from occurring in a length direction of the secondthrough part 420 of the substrate 100 because the second through parts420 extend in one direction.

Moreover, each of the pixel units PU1 to PU3 includes the sub-pixels SP1to SP3, which are arranged in one direction. A direction, in which thesub-pixels SP1 to SP3 of the pixel unit PU1 are arranged, intersects adirection in which a plurality of sub-pixels SP1 to SP3 adjacent theretoare arranged. Therefore, the sub-pixels SP1 to SP3 can be arranged tocorrespond to an arrangement direction of the first through part 410 andthe second through part 420. Accordingly, even when an arrangementdirection of the first through part 410 differs from that of the secondthrough part 420, a non-uniformity of visual influences of the pixelunits PU1 to PU3 is minimized, thereby enhancing an image-qualitycharacteristic of the display device 1.

Moreover, the display device 1 can include the wirings SL1 to SL3, V1 toV3, and D1 to D3, and the wirings SL1 to SL3, V1 to V3, and D1 to D3 areformed to be separated from the through part 400 without overlapping thethrough part 400. Therefore, a flexibility and a durability of thesubstrate 100 are enhanced due to the through part 400. Also, thewirings SL1 to SL3, V1 to V3, and D1 to D3 are prevented from beingstripped because of not overlapping the through part 400, prevented frombeing polluted by a gas such as external oxygen, and prevented frombeing degenerated by moisture.

Kind-based or similar wirings, namely, the wirings SL1 to S13 can extendin one direction and have a curved shape, and can be repeated everycertain period, and thus, a non-uniformity of each pixel unit PU causedby the wirings SL1 to SL3 is reduced or prevented. Also, anon-uniformity of the wirings V1 to V3 and the wirings D1 to D3 isreduced or prevented.

For example, the wirings V1 to V3 and the wirings D1 to D3 which extendin the same direction are formed not to overlap each other, therebyminimizing interference therebetween. Also, curved regions of thewirings V1 to V3 and wirings D1 to D3 correspond to different secondthrough parts 420, and thus, an electrical characteristic of the displaydevice 1 is prevented from being reduced due to interference in curvedportions of the wirings V1 to V3 and wirings D1 to D3.

Moreover, each of the pixel units PU1 to PU3 includes the sub-pixels SP1to SP3 which are arranged in a certain direction. The wirings SL1 toSL3, V1 to V3, and D1 to D3 are respectively connected to the sub-pixelsSP1 to SP3, and are curved to be separated from the through part 400. Tothis end, each of the wirings SL1 to SL3, V1 to V3, and D1 to D3includes a plurality of connections respectively connected to theplurality of sub-pixels SP1 to SP3, a common line, and a body line, andthus, the wirings SL1 to SL3, V1 to V3, and D1 to D3 can be electricallyconnected to the sub-pixels SP1 to SP3 without overlapping the throughpart 400.

So far, the display device 1 has been mainly described, but thedescribed technology is not limited thereto. For example, a method ofmanufacturing a display device is within the scope of the describedtechnology.

FIGS. 8 to 12 are cross-sectional views schematically illustrating aprocess of manufacturing a display device, according to an exemplaryembodiment.

Referring to FIG. 8, an operation of providing the substrate 100 whichincludes a pixel area PA in which the pixel units PU are formed and theseparation area BA which is formed between two adjacent pixel units PUare performed. The substrate 100 can be formed of various materials. Indetail, the substrate 100 can be formed of glass, metal, an organicmaterial, or other materials. In some embodiments, the substrate 100 isformed of a flexible material having flexibility.

An operation of forming the buffer layer 110, the gate insulating layer130, and the interlayer insulating layer 150 on the substrate 100 can beperformed. Also, an operation of forming the semiconductor layer 120 andthe gate electrode 140, which configure the thin film transistor TFT, onthe substrate 100 can be performed. The interlayer insulating layer 150can be stacked on the gate electrode 140, and then, a contact hole CNTcan be formed in order for the source electrode 160 and the drainelectrode 162 to be electrically connected to the semiconductor layer120.

In an operation of forming a contact hole H1, a first through hole 401can be substantially simultaneously or concurrently formed in theseparation area BA. Therefore, an operation of forming the first throughhole 401 in the separation area BA can be performed without adding aseparate mask, and thus, the manufacturing cost is reduced.

The end surface 110 a of the buffer layer 110, the end surface 130 a ofthe gate insulating layer 130, and the end surface 150 a of theinterlayer insulating layer 150 can be exposed through the first throughhole 401. The end surfaces 110 a, 130 a and 150 a can be first endsurfaces 160 a of the first through hole 401. The first end surfaces 160a can be formed to have the same plane. This is because the firstthrough hole 401 is formed in an operation of forming the contact holeH1. In some embodiments, the first end surfaces 160 a are formed in astepped form to have different planes.

Referring to FIG. 9, the source electrode 160 and the drain electrode162 which are electrically connected to the semiconductor layer 120through the contact hole H1 are formed on the gate electrode 140. Thefirst insulating layer 170 can be stacked on the source electrode 160and the drain electrode 162. An operation of forming a via hole H2 inthe first insulating layer 170 can be performed in order for the pixelelectrode 210 to be electrically connected to one selected from thesource electrode 160 and the drain electrode 162.

In the operation of forming the via hole H2, the second through part 420can be substantially simultaneously or concurrently formed in theseparation area BA. Therefore, an operation of forming the secondthrough part 420 in the separation area BA can be performed withoutadding a separate mask, and thus, the manufacturing cost is reduced.

The second end surface 170 a can be exposed through the second throughpart 420. This is because the second through part 420 is formed in theoperation of forming the via hole H2. In this case, the width of thesecond through part 420 can be formed greater than that of the firstthrough hole 401.

Referring to FIG. 10, an operation of patterning and forming the pixelelectrode 210 on the first insulating layer 170 is performed for eachpixel. The pixel electrode 210 can be electrically connected to one ofthe source electrode 160 and drain electrode 162 of the thin filmtransistor TFT through the via hole H2 which is formed in the firstinsulating layer 170.

After the pixel electrode 210 is formed, an operation of forming thesecond insulating layer 180 to expose a center portion of the pixelelectrode 210 and cover an edge of the pixel electrode 210 can beperformed. The second insulating layer 180 can be understood as a pixeldefining layer.

In an operation of forming an opening H3 where the second insulatinglayer 180 exposes the center portion of the pixel electrode 210, a thirdthrough hole 403 can be substantially simultaneously or concurrentlyformed in the separation area BA. Therefore, an operation of forming thethird through hole 403 in the separation area BA can be performedwithout adding a separate mask, and thus, the manufacturing cost isreduced.

The third end surface 180 a can be exposed through the third throughhole 403. This is because the third through hole 403 is formed in theoperation of forming the opening H3. In this case, the width of thethird through hole 403 can be formed greater than that of the secondthrough hole 402.

That is, the first through hole 401 can be formed to have the smallestwidth, the second through part 420 can be formed on the first throughhole 401, and the third through hole 403 can be formed to have thegreatest width. Therefore, the first end surface 160 a, the second endsurface 170 a, and the third end surface 180 a can be formed to have astair structure having a step height. The first end surface 160 a can beformed to protrude farther than the second end surface 170 a, and thesecond end surface 170 a can be formed to protrude farther than thethird end surface 180 a. In FIG. 9, a structure in which the first endsurface 160 a, the second end surface 170 a, and the third end surface180 a are formed to have a step height is illustrated, but the describedtechnology is not limited thereto. An end surface of a through hole canhave one of the structures of FIGS. 4A to 4C.

Referring to FIG. 11, the intermediate layer 220 including an emissionlayer is formed on the pixel electrode 210 exposed by the secondinsulating layer 180. Subsequently, an operation of forming the oppositeelectrode 230, which is opposite to the pixels electrode 210, on thesecond insulating layer 180 to cover the intermediate layer 220 can beperformed. The opposite electrode 230 can be formed over the substrate100. Therefore, although not shown, the opposite electrode 230 can beformed on the first end surface 160 a, the second end surface 170 a, andthe third end surface 180 a.

Subsequently, a fourth through hole 404 having a size substantiallyequal to or less than that of the first through hole 401 can be formedon the substrate 100. The fourth through hole 404 can be formed to passthrough the substrate 100. The fourth through hole 404 can be formed bya laser cutting process, and for example, a portion of the substrate 100can be removed through a fine pattern process using a femto laser.

Referring to FIG. 12, a portion of the substrate 100 corresponding tothe first through hole 401 is removed, and thus, the fourth through hole404 is formed. Therefore, the first to fourth through holes 401 to 404can be formed to overlap each other in the through part 400 which isformed in the separation area BA. Also, a fourth end surface 100 a canbe exposed by the fourth through hole 404. The first to fourth endsurfaces 160 a to 100 a can be understood as the inner surface 400 a ofthe through part 400.

The inner surface 400 a of the through part 400 can be formed in a stairshape to have a step height as illustrated in FIG. 12, and can be formedto have a slope. Also, the inner surface 400 a of the through part 400can be formed in order for a width to be narrowed in a direction fromthe opposite electrode 230 to the substrate 100. That is, the innersurface 400 a of the through part 400 can have a substantially V-shapewith a lower end opened.

In FIG. 12, it is illustrated that the opposite electrode 230 is formedon the second insulating layer 180 and is not formed on the first tofourth end surfaces 160 a to 100 a, but depending on the case, theopposite electrode 230 can be formed all over the substrate 100 withoutbeing patterned. Therefore, the opposite electrode 230 can be formed onthe inner surface 400 a of the through part 400.

An operation of forming the encapsulation layer 300 on the oppositeelectrode 230 can be performed. Although not shown in FIG. 12, theencapsulation layer 300 can be formed in a multi-layer structure wherean organic layer and an inorganic layer are alternately stacked.

The encapsulation layer 300 is formed to seal the OLED and cover theinner surface 400 a. When the encapsulation layer 300 is not formed tocover the inner surface 400 a of the through part 400, moisture orimpurities can flow into one or more material layers in which across-sectional surface is exposed due to the inner surface 400 a anddamage various devices. Therefore, when the encapsulation layer 300 issealed to cover the inner surface 400 a, a reliability of the displaydevice is enhanced.

As described above, according to at least one of the disclosedembodiments, a display device and a method of manufacturing the samewhich enhance a user's convenience are implemented.

It should be understood that the exemplary embodiments described thereinshould be considered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each exemplaryembodiment should typically be considered as available for other similarfeatures or aspects in other exemplary embodiments.

While the inventive technology has been described with reference to thefigures, it will be understood by those of ordinary skill in the artthat various changes in form and details can be made therein withoutdeparting from the spirit and scope as defined by the following claims.

What is claimed is:
 1. A display device comprising: a substrate including a separation region; a thin film transistor disposed on the substrate; a first insulating layer covering the thin film transistor and having a first through hole defined by a first inner surface; a second insulating layer disposed on the first insulating layer and having a second through hole corresponding to the first through hole, and the second through hole defined by a second inner surface; a third insulating layer disposed on the second insulating layer and having a third through hole corresponding to the second through hole, and the third through hole defined by a third inner surface; a plurality of pixels formed over the substrate, wherein the separation region is formed between adjacent pixels of the plurality of pixels, wherein a plurality of through holes are respectively defined by a plurality of surrounding inner surfaces of the separation region, wherein each of the plurality of surrounding inner surfaces passes through the substrate, wherein the substrate has a fourth through hole defined by a fourth inner surface and corresponding to the first through hole, wherein each of the plurality of through holes comprises the first, second, third and fourth through holes, wherein each of the plurality of surrounding inner surfaces comprises the first, second, third and fourth inner surfaces, and wherein the first, second and third through holes have different widths; and an encapsulation layer formed over the substrate and covering the plurality of surrounding inner surfaces of the separation region, wherein the encapsulation layer directly contacts the first, second, third and fourth inner surfaces.
 2. The display device of claim 1, wherein at least one of the plurality of surrounding inner surfaces has a slope.
 3. The display device of claim 1, wherein at least one of the plurality of surrounding inner surfaces has a step shape.
 4. The display device of claim 1, wherein each of the plurality of pixels comprises: a pixel electrode formed over the substrate; an intermediate layer including an emission layer formed over the pixel electrode; and an opposite electrode formed opposite to the pixel electrode and at least partially covering the intermediate layer.
 5. The display device of claim 1, wherein the separation region comprises a first separation area and a second separation area, wherein the first separation area comprises a portion formed between first pixels, adjacent to each other in the first direction, among the plurality of pixels, wherein the second separation area comprises a portion formed between second pixels, adjacent to each other in the second direction, among the plurality of pixels, wherein the first through hole and the second through hole are respectively formed in the first and second separation areas.
 6. The display device of claim 5, wherein the first through hole extends in the second direction, and wherein the second through hole extends in the first direction.
 7. The display device of claim 5, further comprising one or more wirings electrically connected to the plurality of pixels, wherein the one or more wirings do not overlap at least one of the plurality of through holes in a direction crossing the first or second direction.
 8. The display device of claim 7, wherein the one or more wirings extend in one of the first and second directions, and wherein the one or more wirings protrude in the other direction of the first and second directions so as to curve around a periphery of at least one of the plurality of through holes.
 9. The display device of claim 7, wherein the one or more wirings comprise a plurality of wirings, and wherein two of the plurality of wirings, adjacent to each other in one of the first and second directions, are substantially symmetrical with respect to at least one of the plurality of through holes.
 10. The display device of claim 1, wherein the substrate is flexible.
 11. The display device of claim 1, wherein each of the second and third through holes has a length greater than that of the first through hole.
 12. The display device of claim 1, wherein the widths of the first, second and third through holes gradually become smaller from the third through hole to the first through hole.
 13. The display device of claim 1, wherein the width of the first through hole is smaller than the width of the second through hole, and wherein the width of the second through hole is smaller than the width of the third through hole.
 14. A display device comprising: a substrate including a separation region; a thin film transistor disposed on the substrate; a first insulating layer covering the thin film transistor and having a first through hole defined by a first inner surface; a second insulating layer disposed on the first insulating layer and having a second through hole corresponding to the first through hole, and the second through hole defined by a second inner surface; a third insulating layer disposed on the second insulating layer and having a third through hole corresponding to the second through hole, and the third through hole defined by a third inner surface; a plurality of pixels formed over the substrate, wherein each pixel of the plurality of pixels includes a first sub-pixel and a second sub-pixel, wherein the separation region is formed between the first sub-pixel and the second sub-pixel, wherein a plurality of through holes are respectively defined by a plurality of surrounding inner surfaces of the separation region, wherein each of the plurality of surrounding inner surfaces passes through the substrate, wherein the substrate has a fourth through hole defined by a fourth inner surface and corresponding to the first through hole, wherein the plurality of through holes comprise the first, second, third and fourth through holes, wherein each of the plurality of surrounding inner surfaces comprises the first, second, third and fourth inner surfaces, and wherein the first, second and third through holes have different widths; and an encapsulation layer formed over the substrate and covering the plurality of surrounding inner surfaces of the separation region, wherein the encapsulation layer directly contact with the first, second, third and fourth inner surfaces. 